Bombing apparatus for aircraft



May 1', 1945.

H. J. NICHOLS BOMBING APPARATUS FOR AIRCRAFT Filed Co t. 27, 1939 3Sheets-Sheet l ATTO R N vs y ,1 4 H. u. NICHOLS ,37

BOMBING APPARATUS FOR AIRCRAFT Filed Oct. 27, 1939 3 Sheets-Sheet 2 Y mmzd 2 '76 /o'7 y 1 1945- H. J. NICHOLS 2,374,885

I BOMBING APPARATUS FOR AIRCRAFT Filed Oct. 27, 1939 3 Sheets-SheetPatented May 1, 1945 UNl'lED s'mrss harem OFFICE EOMBENG APPARATUS FORAIRCRAFT Harry .l. Nichols, Binghamton, N. Y.

Application Gctober 27, 1939, Serial No. 301,675

25 Claims.

This invention relates to improvements inbombing methods and apparatusfor aircraft. More particularly, it relates to an improved form of smallfragmentation bomb, to a novel form of multiple launching means for suchsmall bombs, and novel forms of fuses particularly adapted for use withthese bombs, and the combination providing bombing means particularlyintended for use by aircraft against moving aircraft. These novel formsof apparatus combine in a high degree the desirable features of safety,practicability, adaptability, and certainty in operation. Various formsof bombs and means for launching bombs are in use. In practice, bombs,when of explosive nature, usually exceed 20 pounds in weight and areindividually suspended in bomb racks. Likewise, there are various formsof bomb fuses, but again with few exceptions they are armed by means ofindividual pull wires which are withdrawn to permit the fuse to arm, thearming force generally being supplied by a wind driven propeller. Suchdevices, while practical for larger bombs, are difficult to apply in apractical manner to small bombs, that is to bombs weighing less thantwenty pounds.

It is therefore an object of the present inven tion to provide novelapparatus particularly adapted to the effective utilization of smallbombs. A further object is to dispense with arming wires and windpropellers for arming bomb fuses, and to provide other novel armingmeans for bomb fuses characterized by safety, simplicity, andconvenience and certainty in operation.

Another object is to'provide a novel means of suspending bombs in a bombrack particularly adapted to the suspension and launching of a pluralityof bombs in each rack.

Another object is to provide a bomb rack characterized by lightness andcompactness.

Another object is to provide novel means for catapulting a plurality ofsmall bombs, thereby to eliminate the possibility of the aircraftstriking the bombs immediately after they are launched.

Another object is to provide novel types of bomb fuses characterized byreliability, simple components, ease of assembly and which can bemanufactured economically in large quantities.

Another object is to provide novel means for arming bomb fuses, whichmeans become entirely armed only in the act of launching.

Another object is to provide a settable time fuse for light bombs whichfuse can be set at a particular time setting and can thereafter be setfor another time or back to the safe setting without deranging thetiming arrangements.

Another object is to provide a novel type of bomb fuse suitable for usewithout change to explode high explosive or low explosive burstercharges.

Another object is to provide in a bomb fuse novel safety features whichwill minimize the hazard of detonation in case the bomb and fuse areexposed to fire, or the bomb is dropped prematurely or in a crash.

Another object is .to provide an economical form of burster charge forlight bombs.

Another object is to provide a novel directimpact type of bomb fusecharacterized by exceptional provisions against being explodedaccidentally.

Another object is to provide a novel and effective method of attackingaircraft in flight.

Other objects will be in part obvious from the annexed drawings and inpart hereinafter indicated in connection therewith by the followinganalysis of this invention.

This invention accordingly consists in the features of construction,combination of parts, the unique relation of the members, and in therelative proportioning and disposition thereof, all as more completelyoutlined herein.

To enable others skilled in the art to fully comprehend the underlyingfeatures of the invention, that they may embody the same by the severalmodifications in structure and relation contemplated by the invention,drawings depicting preferred forms have been annexed as part of thisdisclosure, and in such drawings like characters of reference denotecorresponding parts throughout the views, in which-- Fig. 1 is apseudo-pictorial diagram illustrating a typical collision dive attackaccording to the novel method of the invention.

Fig. 2 indicates the typical manner in which multiple bomb racks may bemounted in a pursuit or interceptor plane.

Fig. 3 shows in a somewhat schematic manner the general arrangement ofthe bomb rack forming part of the invention and indicating the manner inwhich the bombs are suspended in the bomb rack. 1

Figs. 4 and 5 show in detail at right angles the arming sprocket andsprocket retractor mechanism by means of which the bombs may be launchedarmed or unarmed at the optionv of the pilot.

Fig. 6 shows a detail of the catapult feature by means of which thebombs are launched with an initial acceleration over that imparted bygravity and the flight of the plane, illustrating the manner in whichcatapult springs are detached from the chains.

Fig. 7 shows details of the preferred type of construction for the bombrack, and particularly an end plan View of the trip mechanism, inrelease position, on the spacer plate of the bomb rack.

Fig. 8 shows in section details of the trip mechanism by means of whichthe chains are released when it is desired to launch the bomb from arack.

Figs. 9 and 10 show details of the upper and lower or double eccentricpawl retractor device,

as assembled in Fig. 8.

Fig. 11 shows the general form of a preferred type of bomb according tothe invention, including a novel form of time fuse and thecharacteristic rack-teeth in the bomb vanes, and the guide grooves inthe bomb body.

Figs. 12, 13, 14 and show sections of the bomb fuse and bomb of Fig, 11,the sections being taken as indicated on the lines 12-42, 13-43, I i-Mand 15-15, the latter being about double in size to more clearly showthe construction.

Fig. 16 shows in longitudinal cross section a fragment of the lower endof the bomb shown in Fig. 11 and a novel form of direct impact fuse inaccordance with the invention.

Figs. 17 and 18 show a circular horizontal section and a vertical crosssection of the arming ring of the bomb fuses shown in Fig. 16, the crosssection being taken as indicated.

In order that a clearer "perception of the pres ent invention may be hadand of the objects sought to be accomplished, reference is first made toFig. 1 representing in pseudo-pictorial manner the relations between abomber 20 and an attack plane 21 during a typical situation whenemploying the method of collision dive attack in accordance with theinvention.

It is assumed that while the bomber 20 may have a speed exceeding twohundred miles an hour, the attack plane 2| will have a speed at leastone-third greater, and during dives an air speed of one-half or moregreater. Further, that the attack plane can climb at a greater rate thanthe bomber. Hence the attack plane can gain a position well above thebomber and to either side thereof and probably out of range of any guncarried by the bomber. The basic method of bombing attack with timebombs according to the present invention is that of a diving attack on acollision dive or constant angle of approach course between the attackplane and target in a three-dimensional zone. VIhile such an attack canbe delivered from a course approximately over the bomber, attacks canalso be delivered from above and from either side, as illustrated by thediagram.

This latter alternative greatly increases the difliculty of successfulcounter-fire from the bomber, since except for a few seconds during thedive, the attack plane can maneuver to present a constantly changingangle and distance as viewed from the bomber.

It is well known that when two vessels at sea are on 'a convergingcourse, and the bearing of one relative to the other does not change, ifsuch courseis continued collision of the two vessels will ultimatelyresult, regardless of their initial distance and speeds. Such a courseis termed a collision course and refers to their relation on ahorizontal plane. Ordinarily, the course or speed of one vessel or bothis changed to avert collision. However, assuming superior speed for onevessel, that vessel could, merely by maneuvering to keep the bearingconstant, produce a collision regardless of the changes of speed orcourse of the other vessel. Likewise, by maneuvering to obtain and stayon a collision dive course, relative to the bomber, that of the bomber,that is a course substantially converging in space with the attack planecan produce a situation where bombs launched b it will continue on thiscourse into effective range of the bomber. It is of course necessary tolaunch the bombs as circumstances permit to counter-act the bomberdodging either vertically or laterally to avoid the bombs after theyhave been launched, but as will appear from the following description,the means afforded by this invention minimizes the possibility of thebomber being able to do so successfully. To distinguish the method ofattack of the present invention from the collision course method ofattack on moving targets on the ground or water, the former is termedthe collision dive method.

In connection with the following description of the diagram, some basicpoints regarding bombing should be noted. The first of these is that atthe instant of launching, a bomb has imparted to it all the motionalcomponents of the launching plane. Thus the horizontal, vertical anddirectional components of the plane are reflected in the trajectory ofthe bomb. However, as soon as the bomb is dropped, gravity operates toincrease the vertical velocity of the bomb. Neglecting air resistance,the trajectory of a bomb is a parabola tangent to the direction of theairplane at the instant of release, and for some time after the bomb isdropped, it will continue on directly underneath the plane if the planewere to continue on its course. The effect of air resistance is toproduce a gradual lag, termed the air-1ag. of the bomb behind the plane.However, in a drop of only a few thousand feet, this lag is small and isimmaterial in the present instance as will be hereinafter explained.Further, since the bomber, the attack plane, and the bombs afterdropping are all equally affected by any wind present, the wind speedand direction is without material effect. Finally, it does not matterwhat the bombers speed, direction or ele- Vation may be, nor that of theattack plane, so long as the attack plane has speed, and climbing ratein excess of the bomber, and can maneuver to attain a collision divefrom an elevation above the bomber sufficiently great to provide a,

sition of the attack plane is projected vertically downwards to thelevel of the bomber and this point is projected laterally to the bomber.The angle at is the angle between the course of the attack plane and thebearing line of the bomber, the angle 118 is the angle between thehypothetical vertical and the bearing line, while the angle 08 is thehorizontal course angle of the attack plane relative to the bomber.These angles and projections are merely to make clear the geometricalrelations and are of no concern to the pilot of the attack plane, who issolely concerned with the bearing line. The bearing line can be judgedby the unaided eye with considerable accuracy, or more accurately bymean of a simple form of universal pelorus or other simple line of sightdevice.

As the pilot of the attack plane changes course towards the bomber, henotes in moving from point. 3 to point -6 that the bearing line movesforward indicating that his course if continued would pass back of thebomber. He turns his course to the right and downward to increase hisspeed, and at point 4 observes that the bearing line is stationaryindicating that he is now on the collision dive course. It here shouldbe noted that angles a4, a2, and all are equal; also angles b5, b2, andb are equal, hence the line of bearing is constant during this period.The angle of! is a true collision course angle. H continues on thisdiving course past point -2, and at point ll, judging his distance to becorrect. launches a plurality of bombs set to explode at say from 4 to 6seconds at half second intervals, or as desired. As soon as the bombsare dropped, from one rack .22 for example, the pilot pulls up to clearthe bombs, and the bombs go forward in substantially the collision divecourse represented by the dotted lines. The attack plane is in goodposition to start maneuvering for another attack on the same oraccompanying bombers as necessary with the bombs in the remaining racks.

In the situation shown the bombs set at 4 seconds would explode wellabove the target bomber, those set at 5 seconds close above the bomber,and those set at 6 seconds below the level of the bomber. On exploding,the free:- ments of each bomb are projected along the trajectory in aconical pattern, thus in effect continually expanding the dispersionarea of the fragments, as indicated by the dotted circle at the point ofthe diagram. Hence fragments of some of these bombs are virtuallycertain to be in efieotive range of the bomber.

The enemys opportunity for careful aim of his guns was virtuallyrestricted to the course between points i and ll, a period ofapproximately four seconds. at which period the fast diving attack planewas say 3,000 to 2,000 feet away, under which conditions accurategunnery from the bomber would be exceedingly difiicult.

It is obvious that the bomber would probably make some maneuver to foilthe attack. Were such maneuver started before 'the bombs were dropped,the pilot can also change his course to keep the bearing constant, thusmaintaining the collision dive course. Were the maneuver started afterthe bombs were dropped, very little time is available to materiallychange the bombers forward momentum which momentum in the case of aheavy, high speed bomber materially limits its maneuverability. Becauseof the high relative velocity of the attack plane to the bomber, whichmay easily be as great as 400 feet per second, the bombs set to explodeat small. successive increments of time are launched with a highvelocity towards the bomber. which velocity is augmented vertically bygravity.

Furthermore. the pilot can. by swinging or swerving the plane slightlyat the moment of launching the bombs, further disperse the trajectory ofsuccessive bombs, causing them to spread or fall over an area instead ofin a single line, thus obtaining a larger shot-gun pattern. This action,combined with the variable setting of the time fuses of the bombs,enables a veritable barrage of bomb fragments to be laid on and aboutthe normal course of the target thus greatly increasing the probabilityof hits regardless of any sudden change in any direction attempted bythe target.

The method of attack herein described assumes an element of skill on thepart of the pilot, which skill is possessed to a high degree by militarypilots trained in formation flying and bombing. Further, this skill canbe augmented by practice against a towed sleeve target using the meansand following the method of this invention. This is a feature ofgreat.military importance, since practice with most anti-aircraftmethods is exceedingly diflicult and costly.

Actual experience shows that trained pilots unaided by bomb sights canscore a high percentage of hits against a ground target from heights asgreat as 2,000 feet, and it is easier to hit a moving target, followingthe method herein described, than it is to hit a ground target. Withoutfurther analysis, it should be apparent that the method of attack hereindescribed is highly practical, and offers marked advantages inprobability of effective hits and relative security to the attack plane.

Aircraft bombs are generally considered as means for demolitionpurposes, or strafing armed forces or civilian populations. In contrast,the principal intended purposes of the small bombs according to thepresent invention are for use in combating bombers, and for damaging ofdestroying enemy aircraft in the air or on the ground. The type of bombequipped with settable time fuse is primarily intended for attack onaircraft in the air, or freely exposed on the ground. The type of bombequipped with direct impact fuse is primarily intended for attack onaircraft housed in hangars. Hence bombs of the type here described maybe considered primarily as anti-aircraft bombs. For this use, limitedsize and destructive power are advantageous. For purposes ofcomprehending the invention. the bombs can be thoughtof as weighingapproximately five pounds. altho smaller or larger bombs withinreasonable limits can be employed following the teaching of theinvention.

Referring to the figures, showing the bomb racks and bombs in preferredform for carrying out the above method and particularly Fig. 3, thegeneral scheme is to suspend a plurality of light bombs 23, say five, ineach rack 24, the racks being suitable for mounting in multiple in acomparatively small space as shown in Fig. 2, so that a lar e number ofbombs can be carried byeach light plane, of th pursuit and lightinterceptor types.

Mounting of racks in airplanes The mounting of the bomb racks 24 inaircraft is of course primarily the concern of aircraft designers andmilitary authorities. For purposes of understanding the presentinvention, however. it seems desirable to point out that since gravityis not relied upon to launch the bombs, but supplementary catapultaction is provided, the bomb racks may be mounted so that their lengthis substantially in horizontal aspect with relation to the longitudinalaxis of the airplane body, or their length may be inclined upwardly andrear wardly. Furthermore, the bomb rack of the invention is ofrelatively small cross-sectional area, of light and open construction topermit easy accessibility to the mechanism, and the essential controlsfor launching the bombs can be situated remotely from the rack. Thesefeatures facilitate mounting of the bomb racks in multiple, and theymaybe arranged side by side and in layers if desired as shown in Fig. 2.Hence the invention provides unusual latitude and adaptability in theplacement of multiple bomb racks, and contributes towards an eiiicientutilization of the plane load capacity.

Referring to Fi 2, the possibility of mounting multiple bomb racks 24 ininclined aspect inside and near the bottom of the fuselage of anairplane .is,illustrated. Suitable openings in the floor of the fuselageshould of course be provided to permit egress of the bombs. It will beevident to those skilled in the art that the bomb racks of the inventionlend themselves to preferred design considerations, particularly inadaptation to high speed pursuit and anti-bomber types of airplanes.

The bombs 23 are suspended in tandem between pairs of endless chains 25,ofgeneral similarity to bicycle chains. Preferably two of the four tailvanes 26 of each bomb are notched to provide rack teeth 21 adapted tomate with the links of the chain 25. The chains, and-the other vanes notengaging the chains, work in channel guides 28, Fig. 7. The bomb andfuse bodies are provided with grooves 30 in which the chains and guidesare seated, thus to hold the teeth El of the vanes 26 in engagement withthe links of the 1 chain 25. and to position and support the bombs in asecure manner at all times.

Each chain 25 is held taut between two sprockets 3 l32 which are mountedin suitable manner between brackets 33 attached to the spacer plates 36of the bomb-rack frame structure, Fig. 3. The spacer plates 34 are heldin rigid relation by suitable structural members, such as fourcornerangle irons 35 welded to the plates in typical aircraft mode ofconstruction. The guide channels 28 are assembled in notches in thespacer plates by welding in generally similar manner. Each spacer plate34, except the trip mechanism plate, has a central circular hole of asize to permit the bombs 23 to pass thru readily.

Means to be described hereafter is provided to lock the chains 25securel after the bombs are suspended in place, and to release thechains at the option of the pilot to cause the launching of the bombs ina rack. Means is also provided to arm the bomb fuses as the bombs emergefrom the bomb rack on being launched, or to render the arming meansnon-operative to enable the bomb to be dropped unarmed.

The feature here to be noted is the means for catapulting the bombs intandem sequence. The preferred means for accomplishing this is two long,tensioned catapult springs 36, generally imilar to those used forclosing screen doors. Each spring is looped over a pulley El and hookedinto the chain by a special fitting 38 so that a strong spring urgetowards ejection of the bombs is imparted to each chain by the tensionof its associated catapult spring 36. This spring urge, as well as theweight of the bombs, is sustained b the trip device of the releasemechanism (Fig. 7) as will be explained in detail hereafter.

By inspection of the drawings it is readily seen that when the releasedevice is tripped, and the chains thus freed, the catapult springs 36,to-

gether with any gravitational forces present, will propel the bombs fromthe bomb rack. This is primarily to obtain quick launching and to ensurethat the bombs will be thrown entirely clear of the plane.

The chain release mechanism Referring now to Figs. '7 and 8 wherein thedetails of the chain release mechanism are shown,

this mechanism is preferably mounted securely on the next to top spacerplate 34 by a substantial center stud bolt 39 as shown. Each chain issecurely held by a pawl 404l entering in between two rollers of thechain, thus preventing the chain from moving either up or down in thechain guide 28. Each pawl forms a part of and is actuated by a solideccentric ring 42 fitting over an eccentric cam 43 rotatable therein.The eccentric cams, oppositely disposed, may be integral with a flangedpulley piece 44, the whole being rotatably mounted on the center stud39. A flanged cap piece 45 i mounted over the pulley and eccentricparts, the pawls working through notches 46 in the cap piece 45, whichlatter is firmly secured to the spacer plate by screws 41 mounted in theflange thereof. A steel tape 48 runs in the flanged pulley, beingsecured thereto by a small screw Ell passing thru a hole in the tape,and being screwed into a radial hole in the pulley body 44. The tapeends pass thru slots 5| in the cap piece, these slots being disposed sothat the tape can rotate the pulley approximately 180, the pulley beinglimited to this rotation by an arcuate slot 52 in the cap piece in whicha pin 53 mounted in the pulley 44 moves circularly. One end of the tape54 is attached to a stud 55 extending from the piston 56 in a springtube 51 and working longitudinally in a slot 58 in the side of thattube. The spring tube is secured by suitable bracket pieces 60 on thespacer plate 34 beside the trip mechanism. The hollow spring tube hasone end closed except for a central hole in which the piston rod 56'slides, and abutting against this closed end is a long, helicalcompression spring 6!. The other end of the compression spring abutsagainst the head 56 of the piston, tending to push same to the extremeright position of travel permitted by the side screw and slot as shownin Fig. '7. The other end of the steel tape 48 has attached thereto apull wire 62 by means of which the chain release mechanism is tripped torelease the bombs. The pull wire is extended, preferabl by a Bowdencable construction, to the bomb control handle within reach of the pilotor bomber. The bomb control mechanism beyond the pull wire does notcomprise part of the present invention and hence is not shown ordescribed in detail. Suitable control arrangements are provided oncurrent bombing apparatus as is well known to those skilled in this art.

The operation of the chain release mechanism is as follows: To free thechains 25 to permit the bombs 23 to be loaded, the pull wire 62 ispulled outwardly as far as possible as shown in Fig. 7 and secured inplace temporarily. The steel tape 48 attached to the pull wire is thuspulled out, rotating the pulley piece 44 clockwise and by virtue of thedouble eccentrics 43, retracting the pawls Ail-4| from the path of thechains 25. The spring 5! in its tube is further compressed by thisoperation or to the position shown in Fig. 7. When the bombs are inplace in the bomb rack, the pull wire is released, whereupon thecompression spring Bl pulls the tape and pulley piece 40 in the reversedirection, and by virtue of the double eccentrics, the pawls areextended into dotted position between adjacent rollers of the chain,Fig. 8. It is evident that since the eccentrics are on dead center, thepawls cannot be pushed inwardly, but can only be retracted by therotation of the eccentric cams.

To release the chains, the pull wire is again pulled outwardly, therebycausing the eccentrics to retract the pawls it-4i to full line positionFig. 8 and thus release the chain 25.

It is well known that an eccentric permits a relatively high mechanicaladvantage to be obtained, particularly when started from deadcenter asin this case. Hence a relatively light force applied to the pull wire 62enables the pawls to be withdrawn from the chain despite theconsiderable load thereon.

It is to be noted that the compression spring 6| acts on the releasemechanism to hold the pawls always in the extended position, hence thechains can be released only by forcibly pulling the pull wire. Inpractice, accidental operation of the pull wire is guarded against bythe Bowden cable and other suitable safeguards.

The arming mechanism Referring now to Figs. 3, 4 and 5, wherein thedetails of the arming sprockets and retractor mechanism therefor areshown, the arming sprockets 63 are each mounted on trunnion pins 64working in slots 65 of a stationary channel piece 66, termed the guide,and a movable slide piece 61 working in the channel piece, termed theslide. The arming sprockets 63 are mounted to engage with the chains 25on the side opposite the bomb 23, the teeth of the sprocketsextending'between and slightly beyond the rollers of the chain 25 in theusual manner (Fig. Hence when in position of engagement with the chains,as a bomb passes the sprockets, the sprocket teeth pass thru the linksof the chain and encounter and push in trip-pins 88 of the bomb fuse forthe purpose of arming the latter.

To avoid arming the bomb fuse, it is necessary to withdraw the armingsprockets 53 from engagement with the chain, and mechanism for thatpurpose is provided as follows: The stationary channel piece or guide66, with open edge disposed outwardly, is securely mounted betweenadjacent spacer plates 34. The inner closed edge of the guide abuts thebottom of the chain guide 28, and each guide is provided with a slotadjacent the sprocket to permit the sprocket teeth to pass through toengage the chain 25. Short closed slots 65 are cut in opposite sides ofthe guide 66 of a width suitable to provide working clearance for thesprocket trunnion pin 64. The slide 6'! is likewise channel shaped, butoppositely positioned with respect to the guide 65 and of dimensions towork easily inside this I guide. It is also provided with short closedslots H to receive the sprocket trunnion pin (it, but these slots aredisposed at an angle of 45. Near the top of the slide is another shortclosed slot l2 extending longitudinally and adapted to receive a shortguide pin [3- extending inwardly from the side of the guide 66. Thepurpose of this construction is to allow the slide ill to movelongitudinally within limits, and also to permit the lower end of theslide 57 to swing outwardly around the guide pin '53 as a pivot. Atractile spring 74 mounted inside the slide at an angle. one end beingfixed to the slide 67 and the other to the. adjacent spacer plate 34,normally to links.

maintain the slide 61 in' its downward and inward position as shown inFig. 5. A pull wire 15, similar to that provided for the bomb releasemechanism, is attachedto the upper end of the slide 61, and thence isled away to the bomb release controls. In practice this pull wire ispreferably sheathed in a Bowden cable, altho no mishap is liable tooccur because of accidental operation of this pull wire.

The operation is as follows: Normally the tension on the spring 14 holdsthe arming procket 63 so that its teeth engage through the chain Whenbombs are to be loaded in the rack, however, or if it is desired to dropthe bombs safe, the arming sprockets must be retracted. To do this, pullon the arming sprocket wire 15. The slide 6? is thus pulled upwardsagainst the tension of the spring 74, and in so doing, the angular slotsH in the slide cam the trunnion pin 64 outwardly in the slots 65 in theguide 66, retracting the sprocket from engagement with the chain 25. Thebombs can then move past the sprocket position without arming thetrip-pins E8 of the bomb.

Assuming next that the sprockets 63 are to be made operative, the pullwire '15 is released, whereupon the tension spring 'l l acting on theslide cams the sprocket trunnion pin 54 towards the chain 25, and thesprocket 67 teeth again engage with the links of the chain.

It is to be noted that the notches 27 in the edge of the bomb vanes,whereby the bombs are suspended in the chains, must be cut in suchrelation to the trip-pins of the bomb fuse that the trip-pins will nestin the chain between two rollers. Otherwise the chain might push in thetrip-pins prematurely, or else the pins would not be squarely engaged bythe sprocket teeth.

It is to be further noted that the rack teeth 21 in the edge of the bombvanes extend partly through the chain, and hence as they pass the armingsprocket, the rack teeth will strike the sprocket teeth. When thisoccurs, the sprocket is pushed aside, the slide 61 swinging outwardly toenable the sprocket trunnion pins 6 3 to recede from the normalposition. After the rack teeth pass, the tractile spring l l restoresthe sprocket to engaging position for the next bomb. While the sprocketyields to the rack teeth, it ofiers sufiicient resistance to the trippins 68 to push them in without failure.

Catapult mechanism Referring to Figs. 3 and 6, the details or thecatapult mechanism are as follows: A long traction member ofconsiderable strength is provided to exert a propulsive force on eachchain. This member may be in the form of an elastic cord, commonlycalled Sampson cord, but is preferably in the form of a helical steeltraction spring 36 as shown. One end of the spring '15 is adapted to beattached securely to a fixed part at the lower end of the bomb rack, theother end is fitted with the curved metal piece 38 of special form,termed the chain hook, adapted to be inserted between the roller linksor" the chain 25 so that when the tension of the spring 36 is exertedupwards the hook is securely anchored to the chain, but when the springtension is entirely relieved, the hook can be rotated and readilydetached. Due to the special form of the hook, and other suitablearrangements provided, at the end of the catapult stroke, the hook willbe drawn free of the chain, allowing the chain to run freely to ensuresmooth launching of the last bomb in the rack, and to avoid shock on thechain Fig. 6. The spring is looped thru pulley or sheave 3.7 mounted onthe under side of the next to top spacer plate 34. The traction spring,which is wound with initial tension, is of such length when not extendedthat the spring coils come solid when the shank of the hook is drawninto the sheave, in which position the hook is freed of the chain.

The operation of the catapult mechanism is as follows: During theoperation of loading bombs, the catapult springs are. not hooked to thechains.

When the bombs are in place and the chains locked by the releasemechanism, the hook is inserted in the lowest available link in theoutside section of the chain. The traction spring is then drawn down andthe eyelet in the end of the spring is hooked into the slot in the shankof the chain hook 33, which on application of the spring tension islocked in the chain,

On release of the chains, the catapult springs operate to eject thebombs in sequence. At the end of the spring travel, the shank of thechain hook 38 is drawn towards and into the sheave 31, where it isstopped by a check piece. As the shank is drawn into the sheave, thehook portion is drawn free of the chain, which latter is free to rununtil its momentum is expended. Thus the bombs are launched smoothly andwithout material shock to the launching mechanism or bomb rack.

Method of loading bomb in rack Because of the relatively simplearrangements provided by the apparatus, no prescribed procedure ofloading bombs in the rack is necessary. The general steps are: Unhookcatapult springs 36; set sprocket retractor wire 75 to safety positionand secure; pull trip mechanism wire 62 to release position and secure;push the bombs 23 into the rack in tandem, leaving a small space betweenbombs as in Fig. 3 being sure that the last bomb is elevated above thearming sprocket po sition; release trip mechanism wire 63, assuring thepawls 40-4! properly to enter links of chain at desired level; hook upcatapult springs 36; release sprocket retractor wire it to ascertainthat the retractor mechanism works freely and re-set in safety position.Before flight, set time rings of the time fuses to desired settings.Before dropping bombs, release retractor wire l if bombs are to belaunched armed.

The bomb Referring now to Fig. 11, the bomb 23, of streamline form, isprovided with four vanes 28, two of these vanes being notched on theedge to form rack-teeth 2'! of suitable form to mate with the chain 25,while two vanes are preferably left plain as previously explained. Thebomb body (and fuse body B'Sforming a continuation thereof) is providedwith four grooves 36 mating with the chain and vane guides. This is tosupport and steady the bomb, and to ensure proper coordination of thechain links, trip pins 138 of the fuse (to be described later), and thefuse arming sprocket 65. The pilot or heavy end of the bomb has the fusebody attached thereto by heavy threads, or other suitable means ofsecure attachment. The bomb body is provided with a cylindrical barrelT! to receive the burster charge it (loaded in a shot gun shell) andrearwardly thereof a choke'orifice Bil, an expansion chamber 8| and atthe outward end, a safety plug 82' secured in place by solder having alow melting point. The purpose of the choke orifice ti is to restrainthe gases of the explosive charge, thereby to direct the main explosiveforce to the head portion of the bomb, yet to provide some egress ofgases to the expansion chamber 8 I. The purpose of the expansion chamberis to lighten the rear end of the bomb, and to secure effectivefragmentation of that portion of the bomb.

The purpose of the safety plug 82, is in the event of fire, to enablethe gases distilled from the burster charge by heat to escape to theatmosphere, thus preventing a build-up of pressure sufficient to produceauto-detonation of the burstel charge.

The time fuse The time fuse is of a type generally similar to the timefuses long used for shrapnel and antiaircraft projectiles in that it isprovided with a settable, graduated time ring 33 whereby the time ofburst can be set anywhere in a range of 0 to say 15 seconds, in smallincrements. Also, the time ring can be set on safety, at which settingthe time train is incompiete and in case of accidental firing of theprimer due to shocks, etc., premature firing is avoided. There are twotime train rings, one 84 stationary and the other 83 rotatable, eachcontaining an annular, horseshoe shaped groove 85 in the rearward faceof the ring. Fine powder is pressed in these grooves under heavypressure to form the time train, the total length of which is severalinches. Suitable port passage 85 or vents are provided to ignite thetime train thereby carrying the flame from one ring to the other andthence to ignite the detonator 81, whereupon the explosioninstantaneously proceeds via the detonating train to the burster charge.

The principal elements of the time fuse, in addition to the time rings83-84, include the following parts; The fuse body which contains most ofthefiring mechanism and is attached to the bomb body 23 by a screw joint88; the cap 90 which screws on the body to form the point and to retainthe time rings in place; the flash primer 9i located in the axial boreof the cap; the firing pin 92 and firing spring 93, held undercompression by two safety balls 94 housed in a cylindrical sleeve 95;the safety gate 96 rotatably mounted in the axial bore of the fuse bodyand containing a detonating train of tetryl or the like adapted totransmit the detonating wave from the detonator 81 to the burster charge18, the detonating train however being interrupted in the normalposition of the safety gate; the torque spring 91 adapted to rotate thesafety gate into armed position and to trip the firing pin 92 during thearming process; the safety ring 98 Fig. 17 normally restraining thesafety gate, and the two trip-pins 68 radially positioned and adapted tostart the arming process when both are pushed in simultaneously, and theexpansion ring I00 normally holding pins 68 in extended position.

- The operation of the fuse is as follows: Assume that the movable timerin 83 has been moved from safety to some sitting, such as five seconds.Assume next that the two trip-pins 68 are simultaneously pushed inwardlyas far as they will go, which action is effected by the two armingsprockets 63 as the bomb is ejected from the rack Fig. 3. The pushtrip-pins are normally prevented from moving inwardly by a circular wireexpansion ring I00. Normally thetrip-pins engage the safety ring 98,preventing same from rotating. When its pins are pushed inwardly,however, the trip slots l0! move into such position that the peripheryof the arming ring 98 can move or turn by reason of these trip slots.The safety ring is attached to the safety gate, which in turn is underthe spring urge of the torque spring 9?, thereupon rotates, locking thetrip-pins 63 in the inward position. The safety gate rotates thedetonating train. I01 Fig. 13, into alignment with the detonator, and byreason of a square socket hole Fig. 14 which receives the square stem ofthe firing pin 92, causes the latter to rotate. As the head of firingpin rotates (two grooves H33 therein come into alignment with the safetyballs 94, and slide over same, whereupon the firing spring 93 projectsthe firing pin Q2 into the flash primer 9!, exploding same. The flamefrom the primer passes thru the grooves M3 in the firing pin and thenceinto a cross-vent I94 leading to the sta tionary ring powder train H35,which latter is thereby ignited. The time train burns along its lengthuntil opposite the priming pellet in the port 86 leading to the movablering 83, igniting the powder train 85 therein. The powder train in themovable ring burns along its length in the reverse direction until itreaches the priming pellet in the port HIE leading to the detonator 81,causing the latter to be ignited. The detonator explodes and the wave ofdetonation therefrom follows the side port in the safety gate to thecentral port ml, thence to the booster charge and burster charge 13,exploding the bomb.

In the safe position, the ignition train is interrupted at the flashcross-vent I05 by the head of the firing pin, and at the time rings 8384when the movable ring is set on safety. The detonation train isinterrupted at the point where the port leading inwardly from thedetonator 87 meets the safety gate, which latter is normally positionedso that the explosive train liil therein is out of registry with thedetonator as shown in dotted lines in Fig. 13,

Thus it is seen that adequate safeguards are provided to avoid rematureaction of the explosive train. Even in case the detonator were explodedby heat as in a fire, the explosion would be confined to the regionthereof without exploding the main burster charge. With respect to thesafety of the arming mechanism, it should be noted that in order torelease the safety ring, both trip-pins 63 must be pushed insimultaneously against the relatively strong opposing force of theexpansion ring Hi0. Such action can not be produced by dropping thebomb, or striking the bomb, since any single force tending to drive onepin inwardly will operate to tend to move the other pin outwardly. Theexpansion ring is strong enough to prevent premature action by pushingin the trip-pins in handling the bomb.

Thus it is seen that the novel arming features of the bomb provideadequate safeguard against premature arming of the bomb.

The burster charge can be loaded on automatic loading machines providingcomparative safety and economy in cost of loading. The bombs can beassembled, transported and stored separate from the burster charges. Thecase of the cartridge can readily be sealed and water-proofed, keepinthe charge in good condition. The case likewise avoids the possibilityof dangerous chemical reactions between the explosive charge and themetal of the bomb body. Furthermore, the bomb can be readily unloaded ifdesired.

The burster charge, itself may consist of any suitable militaryexplosive such as TNT, amatol or nitro starch. If desired, asupplementary booster charge of tetryl or the like can be loaded in acapsule mounted centrally in the base of the cartridge in place of theusual cap or primer.

Such booster charges are often advantageous to secure certain detonationof relatively insensitive military explosives.

The direct impact fuse The direct impact fuse Fig. 16 is generally ofthe same construction, and may be the same size and shape, as the timefuse so as to be interchangeable therewith. It consists of a body ofrugged construction attached to the bomb by a threaded connection i l 0.It is fitted at the point with a cap ill, likewise by a threadedconnection. This cap is of a material and thickness so as to resistordinary shocks and blows thereon, but to yield to the impact of thebomb when dropped from a considerable height as would be the case inintended use.

The fuse body contains the firing mechanism and explosiveelementscomprising the firing pin H2 extending partly in the cap andpartly in an axial hole in the body and normally maintained in retractedposition by a split ring l 13; the safety gate 56, torque spring 91,arming ring 98, two trip-pins G8, expansion ring H36, and the explosiveelements comprising the detonator 8?, outward detonating train 83, shunttrain 99 and inward train 187. All of these substantially the same inconstruction as those described in connection with Fig. 11.

The operation is as follows: There are'no preliminary arming operations.As the bomb is ejected from the rack the arming sprockets simultaneouslypush the two trippins 68 inwardly. As previously described, the armingring is cleared by the trip slots iill in the trip-pins, enabling thetorque spring 97 to rotate the safety ring 98 and safety gate thru anangle of 45, thereby bringing the ports of the detonator trains of thesafety plug into alignment with the ports of the shunt train in the bombbody. This completes the train of detonation from the detonator to theburster charge.

On impact, the cap H! is pushed inwardly, forcing the firing pin H2 thruthe split ring H3 and stabbing the firing pin into the detonator. Thisexplodes the detonator, and the detonator wave travels outwardly thruthe lower train in the safety gate, thru the side ports and shunt trainin the fuse body back into the safety, gate, and then as inwardly to thecenter port and burster charge in a well known manner. "The safetyfeatures with respect to completing the train of detonation are asbefore. The firing pin is protected from premature arming by the cap. Inthe event the bomb is dropped without being armed as described, thefiring pin may be driven into the detonator as described above,exploding same. However, the train of detonation will be broken as thewave leaves the safety gate, and the burster charge will not beexploded. It will be understood by those skilled in the art that I like.

plemmtary explosivematerial; is provided at the I I other coolingeffects will render these gases in- .efiectivetor-start the detonation.I I I II The various detonating trains inIthis fuse, like= I I those ofthe time fuse, aretpreferablygloadcd'with 3 I =tetryl, rammed; in placeand protectedatthe ex- I I posed ends by coating with a tough,water-proof varnish such as .a' celluloseacetate lacquer or the Tetrylischaracterized by being compare-I I :tively easy to detonate by aiulminate charge, but will :not be detonated by heator flame; I IWithout further description or analysis, it is considered evident that;the bombing equipment I I I I inaccordance with the inventioncombmesin aI I :high degree practicability; versatility, efficiency,

: convenience,- and other advantageous features I I WhatiscIaimed is: II I I I Lin .a bomber airplane: a multiple bomb I I I catapult carriedbytheiplan e, aplurality of bombs I mounted: in tandem therein,andcarrier means point of' change of direction. Hence, altho the II Igasesfrom the detonator and explosive train may leak into various partsof the fuse; expansion and I in tandem, propelling meanstendin todischarge 1 I I I said bombs forwardly; means .for. releasing the chainmeans, andmeansior arming the bombs I I they are propelled from the Ihanne1 .I I 8.-Gatapult apparatus according to claim 7 in I I I I whichthe arming means on the bombs includes II I a depressible pin; and meanscooperating there- I withior. depressing saidpin as thebombs are I Iindividually as ejected. I I

' El A catapuit bombracl: =for airplanes-inclum ingmeans for mounting aplurality of relatively I small bombs in; tandem relation, saidmountingmeans including I a pair of :spacedendless chains movably mountedonLsprockets and: adapted to 9:"; coact with the bomb for holding thesame. sus- I I pended in the: rack; I propelling means. coacting I Iwith said. chains, mean ior holding the chains I I against Iniovement,and I means-for; releasing: the I chains whereby they mayimov'e toeicctthebombs from. the rack in tandem relation; I I I I I I i 10;Inanapparatus according to olaim 9 in I I II I eluding means coupledwiththe chains for accel- I I I I I I I I I I I i I in said. catapultfor carrying, arming, and eject- I crating their movement, but,automatically Iun- 1 I I I I I I I mg: said plurality: of bombssubstantially simul '25 coupledtherefrom at the end ofsaidacceleration.I I I I taneously forwardly along the line of flight in ll; An apparatusaccording to claims includtandem formation. I I I I I :ing: springpropelling means acting upon said 2. Bombing apparatus as set: forthin.claim .l I II I I chains :for accelerating; their movement to cata- I II I I I I I I I in which said bomb catapult is provided with a I I I=pult the:-bombs out through the .ends of saidrack. 1 I I I f I i I I iI I I I I I pair; of parallel: conveyorchains; of a length 3? I 12. An;apparatus according to claim 9 includ i I I I & suiifieientto carry aplurality ofbombsiintandem; I I ing 'meansu'ndersthe control of th:pilotfor re- I I I I I I I :3. In; abomber. airplane, a plurality of Iindi I leasing the holding means for said chains where- I I I I I I I II I viduallyoperable elongated multiple bomb cata -I I I I .bythebombsmaybeejected: I I I I I I I I I I I pults mounted side by sidea into theconstruction I 1.3.; An apparatus according to claim :9 include I I I Iof the plane and extending forwardlyand slightly 5 :ing' means for:moving the holding .means out of downwardly with: respectxto the:longitudinal axis I I i of the plane; in which each of saidbombcatapults. I

: I I I is; adapted :tocarry 2LT plurality of bombs in tan- I I dem, andincludes chain conveyor means and: I I

means for forcibly projecting said bombs out through the forward end ofsaid catapult in tandem salvo.

4. A bomb catapult for airplanes comprising an elongated structureadapted to hold a group of bombs in tandem and disposed in alongitudinal direction with respect to the length of the plane, chainconveyor means in said structure for carrying the bombs in tandem, meansfor urging said chain conveyor means rapidly forward, and means forreleasing saidchain conveyor to eject the bombs forwardly as a group.

5. A bomb catapult apparatus according to cl'aim 4 in which the c0nveyorand ejectin means comprises a pair of endless conveyor chains arrangedsubstantially in the same plane, and spring means cooperating with saidchains to propel the same and the bombs carried thereby.

6. A bomb catapult for airplanes comprising a guide channel adapted tohold a plurality of bombs in tandem, structural means supporting saidchannel in a longitudinal direction with respect to the plane and withits dischar e end forward, movable endless chain means in said channeladapted to carry a plurality of bombs in tandem, and spring means forrapidly moving said chain means longitudinally and; forwardly in thechannel to eject said plurality ofbombs in tandem.

'7. A bomb catapult for airplanes comprising a guide channel adapted tohold a plurality of bombs in tandem, structural means mounting saidchannel in a longitudinal direction with. respect to the plane and withits discharge end forward, movable chain means within the channeladapted to carry a plurality of unarmed. bombs cooperative: relation tosaid. chains whereby; said I i I chains are free" tomove in eitherdirection I I t 14;: A catapult: bomb rack for airplanes I com- I I Iprisinga skeleton structural assembly having a I I I bomb channel intheaxis thereof and adapted to I I mount in tandem therein a, plurality ofbombs having individual arming means and support members therefor, andbomb supporting means associated with the rack including a pair ofmovable flexible carriers in said rack coacting with the support memberson the bombs for holding same in launching position within the rack,means for propelling said carriers to discharge the bombs from saidrack, and means coasting with said flexible carriers for arming th bombsindividually as they are discharged from the rack.

I5. A catapult bomb rack for airplanes comprising a structural assemblyadapted to mount two: or more bombs having arming means and supportingmeans associated therewith, apair of movable chains stretched in saidrack coacting with the supporting means on the bombs for holding them inlaunching position within the rack, and means coacting with said chainsfor arming the bombs as they are discharged from the rack.

16. A catapult bomb rack for airplanes including a plurality ofperforated spaced supporting plates, angle irons connecting said platesto form a rigid rack structure adapted to be carried by the airplane,sprockets mounted on the upper and lower supporting plates at oppositeends of said rack, a pair of co-planar endless chains passing, aboutsaid sprockets for supporting a plurality of unarmed bombs in tandemrelation by engagement with opposite tail fins of the bombs, guide meansfor said chains, propelling means for said chains, and means forreleasing the chains to carry the bombs out of the rack, said releasingmeans being under the control of the plane operator and includingholding means cooperating with the links of the chain.

17. An apparatus in accordance with claim 16 including spring propellingmeans cooperatingwith the sprocket chains for accelerating theirmovement to eject the bombs.

18. An apparatus in accordance with claim 16 including means coastingwith the chains adapted to arm the bombs as they leave the sprocketwheel out of engagement with the sprocket chain.

21. An apparatus in accordance with claim 16 including sprocket wheelscooperating with the chains having teeth passing between the ipintlesthereof to arm the bomb as the bomb passes said sprocket wheels, andmeans for moving said sprocket wheels out of engagement with the chains,said means being disengage'able at the will of the pilot and uponrelease of said disengageable means automatically returnable to operableposition. 1

22. In a bombing mechanism, a catapult comprising a pair of releasablebomb conveyor chains, a bomb mounted between and carried by said,conveyor chains including a streamlined body and head with a normallyunarmed fuse with fuse arming means attached to said head, bomb armingmeans mounted on said catapult,

and notched guide fins at the tail end of said body for supporting thebomb in said bomb catapult by engaging with said conveyor chain and forregistering said arming means in predetermined relation to said conveyorchains, thereby to enable said bomb arming means to coact with said fusearming means when the bomb is catapulted.

23. Bombing apparatus in accordance with claim 22 in which said fusearming means is adapted to be actuated on release of the bomb conveyorchains.

24. In bombing apparatus, in combination, an aerial bomb, a catapultingbomb rack therefor including bomb arming mechanism, and a bomb fuse forsaid bomb comprising firing means and detonating means, rotary meanswithin the fuse adapted to rotate said detonating means from ineffectiveto effective position, and safety means entirely inseparable from thefuse and independent of the firing means for normally restraining saidrotary means and adapted by co-action of the aforesaid bomb armingmechanism to remove such restraint.

25. In bombing apparatus, in combination, an aerial bomb, a catapultingbomb rack therefor including bomb arming mechanism, and a fuse for saidbomb including therefor detonating means normally maintained in unarmedposition, firing means and arming means within the fuse for saiddetonating means adapted to be acted upon by said bomb arming mechanismto arm said detonating means independently of said firing means.

1 HARRY J. NICHOLS.

